Electrical test probes having spring-loaded contact tips are employed in automatic circuit board and electronic circuit test systems and for other similar purposes in which electrical contact is made between a circuit or device and one or more test points. The spring probe generally comprises a metal sleeve having a plunger slidably disposed therein and having a helical coil spring surrounding the plunger and disposed within the sleeve for urging the plunger to a normally outward position. The outer plunger end includes a probe tip of intended configuration to contact an associated terminal of a circuit board or other device.
The coil spring has electrical resistance and inductance which for some purposes detracts from or impairs the electrical performance of the probe. The length of the probe is also governed by the intended length of the coil spring to provide the requisite spring action on the probe tip, and for some purposes the probe length is greater than desirable. The degree of spring action is not controllable in a spring probe employing a coil spring without altering the characteristics of the coil spring itself.